Performance of goldfish trained on multiple schedules of response-independent reinforcement.

In 3 experiments, 2 with appetitively elicited target striking and a 3rd with aversively elicited shuttling, 42 goldfish were trained on variable time schedules of response-independent reinforcement with or without a correlation between conditioned stimulus color and probability of reinforcement. Unlike pigeons in keypecking situations, Ss responded strongly even on uncorrelated schedules. In the 2nd and 3rd experiments—in which density of reinforcement and contingency were unconfounded—the level of response to a color was determined only by probability of reinforcement, independently of stimulus-reinforcer contingency. Except on the assumption that both measured responses are products entirely of adventitious response-reinforcer control, which seems particularly unlikely in the case of shuttling, the results cast doubt on the generality of the contingency interpretation of classical conditioning. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimal radiation pattern of an array in the presence of two directional interferences

In the presence of two directional interferences, the radiation pattern of an adaptive array can be expressed in terms of the powers of the sources and their directions of arrival. This is used to illustrate the performance and operation of adaptive arrays in the case of multiple jammers. In particular, the case of main-beam jamming is examined.     

Effects of sex of subject and method of block presentation on the Tactual Performance Test.

Investigated the relationship of sex and presentation-format (randomized vs standardized) variables to formboard performance, memory, and localization scores obtained on the Tactual Performance test of the Halstead-Reitan Neuropsychological Test Battery. 26 male and 26 female undergraduates served as Ss. Memory scores were affected by presentation format, and localization scores were significantly affected by sex. A strong trend suggests that presentation format may also have had an impact. (5 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Programmed therapeutic messages as a smoking treatment adjunct: Reducing the impact of negative affect.

Maintaining treatment gains remains a challenge to smoking cessation programs. Smokers prone to negative affect are most likely to relapse. In an effort to improve maintenance, a standard cognitive behavioral treatment was supplemented with the provision of computer-controlled audiotape players containing personalized therapeutic messages. Either the standard treatment alone or the standard treatment plus 2 months use of the tape player were provided to 41 smokers. No outcome difference was found between the 2 conditions during the 1-year follow-up. (The combined 1-year abstinence rate was 61%, with 34% continuously abstinent.) The frequency with which participants used the device predicted both posttreatment coping skill use and smoking rate. Most notable was an interaction between treatment condition and negative affect. Provision of the devices negated or reversed the usual association between negative affect and poorer outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The emergent coordination of cognitive function.

1/f scaling has been observed throughout human physiology and behavior, but its origins and meaning remain a matter of debate. Some argue that it is a byproduct of ongoing processes in the brain or body and therefore of limited relevance to psychological theory. Others argue that 1/f scaling reflects a fundamental aspect of all physiological and cognitive functions, namely, that they emerge in the balance of independent versus interdependent component activities. In 4 experiments, series of key-press responses were used to test between these 2 alternative explanations. The critical design feature was to take 2 measures of each key-press response: reaction time and key-contact duration. These measures resulted in 2 parallel series of intrinsic fluctuations for each series of key-press responses. Intrinsic fluctuations exhibited 1/f scaling in both reaction times and key-contact durations, yet the 2 measures were uncorrelated with each other and separately perturbable. These and other findings indicate that 1/f scaling is too pervasive to be idiosyncratic and of limited relevance. It is instead argued that 1/f scaling reflects the coordinative, metastable basis of cognitive function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Low-threshold GaAs/GaAlAs buried heterostructure laser with an ion-beam-etched quarter ring cavity

GaAs/GaAlAs buried quarter ring lasers with a constant stripe shape along the cavity were fabricated by ion beam etching. Threshold currents of 23 mA were obtained for 2 ?m-wide and 430 ?m-long cavities on a wafer, for which the broad-area threshold current density was l.7 kA/cm2. This structure leaves the rest of the wafer free for optoelectronic integration.     

Creep of udimet 500 during thermal cycling: II. The time to failure

The effect of rapid temperature cycling on the time to failure of Udimet 500 superalloy was investigated. It was found that the time to failure is determined only by the minimum creep rate and not by the thermal history. For this reason the time to failure under thermal cycling conditions is longer than the time to failure calculated from isothermal data.     

A genetic test of the effects of mutations in PKA on mossy fiber LTP and its relation to spatial and contextual learning

Using a genetic approach, we assessed the effects of mutations in protein kinase A (PKA) on long-term potentiation (LTP) in the mossy fiber pathway and its relationship to spatial and contextual learning. Ablation by gene targeting of the C beta 1 or the RI beta isoform of PKA produces a selective defect in mossy fiber LTP, providing genetic evidence for the role of these isoforms in the mossy fiber pathway. Despite the elimination of mossy fiber LTP, the behavioral responses to novelty, spatial learning, and conditioning to context are unaffected. Thus, contrary to current theories about hippocampal function, mossy fiber LTP does not appear to be required for spatial or contextual learning. In the absence of mossy fiber LTP, adequate spatial and contextual information might reach the CA1 region via other pathways from the entorhinal cortex.     

Creep of udimet 500 during thermal cycling: II. The time to failure

The effect of rapid temperature cycling on the time to failure of Udimet 500 superalloy was investigated. It was found that the time to failure is determined only by the minimum creep rate and not by the thermal history. For this reason the time to failure under thermal cycling conditions is longer than the time to failure calculated from isothermal data.     

Effects of nicotine dose, instructional set, and outcome expectancies on the subjective effects of smoking in the presence of a stressor.

The balanced placebo design (BPD) was used to evaluate the independent effects of nicotine dose and smoking-related expectancies on self-reported anxiety, urge to smoke, and withdrawal symptoms. After anxious mood was induced, participants smoked either a de-nicotinized cigarette or one with standard nicotine content. Nicotine dose was crossed with instructions that the cigarette was either de-nicotinized or standard. Nicotine cigarettes produced greater anxiety reduction than de-nicotinized cigarettes. Nicotine instructions attenuated anxiety only among those who held relevant expectancies. Nicotine dose and instructional set interacted such that either nicotine cigarettes or instructions that the cigarettes contained nicotine were sufficient to reduce urge to smoke. Implications of these findings and methodological issues regarding use of the BPD with cigarettes are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)